Insole For Shoes

ABSTRACT

An insole is proposed for a shoe. The insole has a lower side configured to face a shoe outsole, and an upper side opposite the back side for contacting the sole of a shoe wearer&#39;s foot. A projection projects upwardly from the upper side. The insole is configured to position the projection at a location of the user&#39;s foot directly under a medial side of the cuboid bone. A kit for assembling an insole for a shoe is also provided. A method for treating a disorder of the foot is further provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation in part of U.S. patent application Ser. No. 13/392,480, which in turn is a U.S. national stage of application No. PCT/EP2010/062410, filed on Aug. 25, 2010. Priority is claimed on European Application No. 09168688.1 filed Aug. 26, 2009 the contents of all of said documents are incorporated herein by reference.

FIELD

The invention relates to an insole for a shoe. The invention further relates to methods of treating disorders in the foot such as cuboid syndrome.

BACKGROUND

The cuboid bone of the foot is located in the lateral midfoot, surrounded by the calcaneus posteriorly, the fourth and fifth metatarsals anteriorly, and the navicular and lateral cuneiform medially. Calcaneal-cuboid (CC) joint function is dependent on midtarsal joint mechanics, since the navicular and cuboid bones move essentially in tandem during gait. The mechanics of the CC joint are highly variable.—The principal movement at the CC joint is medial/lateral rotation about an anterior/posterior axis with the calcaneal process acting as a pivot. The rotation has been described as pronation/supination and obvolution/involution. The term Inversion/eversion is generally used herein.

FIGS. 3, 4A and 4B shows a right foot plantar view of the bones of the human foot. The cuboid bone 20 is dorsal to the toes and is adjacent to the navicular bone 22. A longitudinal axis a of the foot extends from the middle of the calcaneous (heel) bone 24 to the tip of the index (second) toe 25.

The cuboid bone rotates as much as 25° during inversion/eversion about an axis that passes from posteroinferior (plantar aspect of the foot) to anterosuperior (dorsal aspect of the foot) at an angle of roughly 52° (range,) 43°-72° with respect to the ground. In addition to inversion/eversion, there is some evidence that posterior-anterior distraction of the CC joint also occurs during the gait cycle.

The midtarsal joints (talonavicular and CC) are thought to play a vital role in the transition of the foot from a mobile adapter during weight acceptance to a rigid lever during push-off and in rearfoot-to-forefoot load transfer during propulsion.

With respect to the gait cycle, the cuboid is locked prior to heel strike. The cinching mechanism of the fibularis longus tendon around the cuboid is essential to the control of the transverse arch's feature of stability with adaptability.

Load transfer should occur from the lateral-to-medial forefoot to facilitate an effective “windlass effect” when the metatarsophalangeal joints extend. During early stance when the calcaneus is everted, the forefoot tends to flex and extend more; during push-off, the calcaneus is inverted, and the forefoot is more rigid. This phenomenon is attributed to the orientation of the talonavicular and CC joint axes, which become parallel during calcaneal eversion, increasing motion in these joints and in the forefoot in general. Conversely, calcaneal inversion during push-off causes the midtarsal joint axes to diverge, which reduces mobility in the midtarsal joint and the forefoot. Forefoot flexion/extension may increase when the calcaneus everts, even though cuboid and navicular mobility decrease. This is in part affected by the windlass effect in which through dorsal flexion of the toes and concomitant plantarflexion of the Metatarsal heads, the plantar aponeurosis winds around the Metatarsophalangeal Joint, pulling the heel and toes closer together, raising the longitudinal arch and locking the bones together for the rigid lever of propulsion.

During midstance the cuboid bone will need to unlock to allow the navicular to rotate and initiate propulsion. The rotation of the navicular allows for forefoot pronation, independent of hindfoot motion, bringing the big toe in position for effective push-off.

The closed movement cycle of a walking human involves not only the foot but also the entire lower extremity. For this purpose, the foot must contact the ground. When the foot contacts the ground, each movement of parts of this foot affects all of the other parts of the corresponding leg.

The walking movement of each leg is divided into the stance phase and the swing phase. The stance phase is further differentiated into three component phases; see FIG. 2 which illustrates the human gait using the example of the right leg.

The contact phase, the first component phase of the stance phase, begins by the foot striking the ground with the outer edge of the heel. The tibia is starting to rotate internally and the inner side of the foot is raised slightly. Continuing in this phase, the foot rolls further inward until the metatarsus supports the full weight. The ankle pronates (rolls inward) by up to 8° so that the foot prepares for the propulsive phase. In short, the foot has absorbed the shock of contact with the ground, adapted to the uneven surface, and flattened out. The contact phase is concluded when the forefoot is in full contact with the ground. The primary function of this phase is to absorb the shock when striking the ground and adapt to different ground surfaces (adaptation).

The second component phase of the stance phase, the midstance phase, begins with the forefoot fully contacting the ground and ends with the heel lifting off from the ground. Body weight travels over the foot when the tibia and the rest of the body move forward. The primary function of the foot in this phase is to store, with as little loss as possible, the energy gained during the first component phase and reserve it for the propulsive phase, comparable to a bouncing rubber ball.

The third component phase of the stance phase, the propulsive phase, begins with the lifting of the heel; the muscles, ligaments and tendons are flexed. The forefoot and hindfoot together form a springboard by which the toes lift the weight of the body (forward) off the ground and the foot moves from dorsiflexion to plantarflexion. The body is propelled forward during this component phase, and the weight is shifted to the other foot as it makes contact with the ground. This phase takes up 33% of the entire stance phase.

At the start of this third component phase of the stance phase, the subtalar joint supinates (rolls outward) and ensures that the center of pressure remains under the outer side of the forefoot, which ensures that the cuboid bone locks with the navicular bone. The foot transforms from mobile adaptor to rigid lever in order to propel the body forward during this phase. The dorsi flexion of the toes and plantar flexion of the Metatarsal heads pulls the plantar aponeurosis around the distal Metatarsophalangeal joints, raising the longitudinal arch and locking the bones, preparing the foot for propulsion. This ingenious way of converting the supple landing foot into a rigid propulsion foot is called the Windlass effect. This entire function is affected by shoes, both the rigidity of the sole and more importantly the toe box which prevents full and proper dorsi flexion of the toes and therefore impairs this Windlass Effect. The cuboid is exceptional in that it is the only bone in the foot that articulates with both the metatarsal joint (tarsometatarsal articulation or Lisfranc joint) and the tarsal joint (midtarsal or Chopart's joint); further, it is the only bone that links the lateral column with the transverse foot arch.

During a normal stride, locking of the cuboid with respect to the navicular prior to heel strike provides for a very strong support through the participating ligaments and, in so doing, spares the muscles which would otherwise be severely tasked, since the vertical forces at this moment can exceed 125% of the body weight. Towards the early midstance phase, as the foot moves from heelstrike towards toe-off, unlocking of the cuboid is required. Co-contraction of the fibularis longus (also known as peroneus muscle) and tibialis anterior takes place prior to heel(s) strike to lock the cuboid, which leads to a transverse pulling and supporting effect which substantially aligns the bones of the midtarsal region and reflects the 3 Dimensional movement described in supination and pronation. The supporting effect of the tendons of the peroneus longus muscle around the cuboid is essential for control of the function of the transverse arch for stability and adaptability. To reach the end of the propulsive phase where the big toe leaves the ground, the foot has to rotate internally, otherwise known as pronation. If the cuboid does not release or unlock, the foot remains in a rigid closed packed position, impairing the navicular rotation and ultimate push-off by the big toe which is called a “toefoot” function. Toefoot function allows the force of push-off to transfer through the first Metatarsal ray, navicular, talus and up the tibia/femur which is an effective means of force transfer as it is all joint mediated. It also allows for all of the hamstrings to contribute to the activity including the Adductor Magnus which with the short head of Bicep Femoris is considered the fourth hamstring.

Midfoot rigidity one aspect of which is caused by the locking of the cuboid, causes the push-off to be more lateral on the foot which is called a “heelfoot” function, and the stress follows the lateral side of the foot through metatarsals four and five, the cuboid, calcaneus, and up the lateral aspect of the chain, through the fibula to the fibular head where the stress does not have a boney joint pathway to continue, creating stress/strain to the lateral aspect of the knee, IT Band and causing more involvement of the lateral hamstring and less by the medial hamstring as the push-off migrates more laterally. This would lead to reduction of muscular force, endurance, balance and proprioception. Moreover, there would be an increased tendency for lateral sprains because this structure is basically a raising structure (supination) and the person could not achieve a functional lowering (pronation). In such a case, the natural flow of force through the foot illustrated in FIG. 2 would be interrupted or limited.

Dorsiflexion of the big toe contributes to the windlass effect and is made possible because of the contraction of the Extensor Hallicus Longus muscle. With the dorsiflexion of the big toe, the sesamoid bones of the Flexor Hallicus Longus muscle move forward and upward around the head of the metatarsus and thus maximize the tension of the Flexor Hallicus Longus muscle as a passive support to the arches of the foot in addition to the winding of the plantar aponeurosis around the Metatarsal head, approximating the distance between the heel and toes, raising the longitudinal arch and locking the bones to become a rigid lever.

FIG. 1 shows the right-foot gait and the stance phase subdivided into its three subphases: the contact phase, midstance phase and propulsive phase.

FIG. 2 illustrates the natural flow of force through the foot in more detail. The flow of force begins slightly to the side in the heel and then flows forward between the first and second metatarsal bones and exits the foot through the big toe.

Prior research into problems of the lower extremities in humans provides evidence that certain foot-related disabilities which are often found in persons who wear shoes consistently and for long periods are generally absent in the feet of unshod populations. Examples of such disabilities include “cuboid syndrome”, hallux valgus, plantar fasciitis, bunions, hammertoe, and generally painful feet. In shod populations, shoes commonly limit the natural movements of the foot and the sequences for adaptive muscle activation required for stabilization of the foot structure before and during full weight bearing and during toe-off. In habitually unshod persons, the foot muscles have freedom of movement and the joints remain flexible. Therefore, functional disorders are rarely found in these persons.

Cuboid syndrome is a relatively common, painful condition of the lateral midfoot. The syndrome is thought to arise from subtle disruption of the arthrokinematics or structural congruity of the calcaneocuboid (CC) joint in the foot. The symptoms of cuboid syndrome can resemble those of a ligament sprain. The syndrome can develop insidiously or after a traumatic event (eg, ankle sprain), and may be difficult to identify clinically or with imaging. Several causes have been proposed for cuboid syndrome, including excessive pronation, overuse, and inversion ankle sprains. Although the precise pathomechanic mechanism is unclear, cuboid syndrome is thought to arise from forceful eversion of the cuboid while the calcaneus is inverted, with resultant disruption of CC joint congruity. Loss of congruence between the calcaneus and cuboid, which may be imperceptible during examination, may be the source of lateral foot pain. The peroneus longus may play a role in the development of cuboid syndrome, since this muscle imparts an eversion moment on the cuboid. Impaired peroneus longus function may affect CC joint stability.

Various rehabilitative insoles have been proposed for alleviating the health problems described above. For example, U.S. Pat. No. 5,404,659 suggests an insole for a shoe in which a very extensive projection is provided for stimulating the golgi tendon organ. This projection makes up almost 50% of the entire surface area of the insole

European patent applications EP 1 041 947, EP 1 423 062, U.S. Pat. No. 6,510,626 and U.S. patent publication #2002/0014024 A1 also disclose various insoles.

U.S. Pat. No. 2,423,622 A discloses a flat shoe insole having a virtually square-shaped elevation beneath the cuboid bone of the shoe wearer which is aligned laterally alongside the longitudinal axis of the suggested shoe insole.

U.S. Pat. No. 3,421,518 likewise suggests an elevation on the outer side in the elongated position of the cuboid bone of the shoe wearer for the insole of a shoe.

The technical teaching of U.S. Pat. No. 2,154,997 consists in the construction of a bottom foot lining in the elongated position of the cuboid bone of the shoe wearer which is now not only on the outer side but over the full width of the foot.

SUMMARY

The present invention relates to the inventors' discovery that a dynamic locking and unlocking of the cuboid bone is important for a natural gait when wearing shoes, and that this can be achieved by applying a narrowly targeted, selective pressure against the user's foot which is essentially limited to pressure applied to the medial side of the cuboid bone where that bone borders the navicular bone on one side and the calcaneus bone on another side. This “unlocks” the cuboid bone during the “stance” phase of the user's stride and aids in pushing off with the big toe during walking or running.

During a normal stride, locking of the cuboid with respect to the navicular provides for a very strong support through the participating ligaments and, in so doing, spares the muscles which would otherwise be severely tasked, since the vertical forces at this moment can exceed 125% of the body weight. Towards the middle of the stance phase, unlocking of the cuboid is required after the locking has taken place prior to the stance phase. A co-contraction of the fibularis longis (also known as peroneus muscle) and tibialis anterior takes place, which leads to counter-contractions and brings about a transverse pulling and supporting effect which substantially aligns the bones of the midtarsal region. The supporting effect of the tendons of the peroneus longus muscle around the cuboid is essential for control of the function of the transverse arch for stability and adaptability. To reach the end of the propulsive phase in which the big toe leaves the ground, the foot must now rotate internally, otherwise known as pronation. If the cuboid were not released or were unlocked, each joint would lose a small portion of its movement and, therefore, also a small portion of its forces needed for toe-off: this would lead to inhibition of muscular force, endurance, balance and proprioception. Moreover, there would be a tendency for lateral sprains because this structure is basically a raising structure (supination) and the person could not achieve a functional lowering (pronation). In such a case, the natural flow of force through the foot illustrated in FIG. 2 would be interrupted or limited. Before the big toe leaves the ground, it is together with the four small toes of the same foot dorsiflexed. The first metatarsal bone together with the other metatarsal bones of the same foot are plantarflexed. The dorsiflexion of the big toe is known as the windlass effect and is made possible because of the contraction of the extensor hallicus longus muscle. With the dorsiflexion of the big toe, the sesamoid bones move forward and upward around the head of the metatarsus and thus maximize the tension of the flexor hallicus longus muscle.

According to one aspect of the present insole and treatment method, the cuboid bone is unlocked during the forward phase by a straight line elevation of 35 degrees in the soft and elastic gel material. That corresponds to the degree of articulation of the cuboid bone medial to the adjacent foot bones. The complete functionality of the foot with the correct footwear will be reached and it will train and maintain the muscles of the foot over a lifetime, solely through the uses of the patented and protected insole and footwear.

According to one aspect, we disclose an insole that works inside footwear to train and rehabilitate, and prevent a variety of foot, leg and back ailments, in addition to enhancing the users overall performance.

In one aspect, the present insole comprises an upwardly projecting structure configured to promote a progressive treatment program to re-educate and remodel the foot towards a biomechanical ideal. The system stimulates a natural biofeedback (reflex) response to strengthen and realign the foot's musculoskeletal system.

According to one aspect, we disclose an insole for a shoe, comprising:

-   -   a lower side configured to face a shoe outsole;     -   an upper side opposite the back side for contacting the sole of         a shoe wearer's foot; and     -   a projection projecting upwardly from the upper side;     -   wherein the insole is configured to position the single         projection directly under a medial side of the cuboid bone of         the shoe wearer where the cuboid bone borders a navicular bone         on one side and a calcaneus bone on another side for selectively         applying a targeted pressure which is essentially limited said         location of the user's foot for unlocking of the cuboid bone         during the stance phase of the user's stride. The term         “selectively” as used herein means that the insole has only a         single projection that exerts pressure against the sole of the         user's foot, and the location of this pressure is selected to         the region of the foot described above.

The projection may have a base which has a size relative to the size of the insole which is up to about 25%, 20% or 15%, or which is in the range of about 4% to about 8% thereof. Furthermore, the projection may have a height in a range from about 3 mm to about 20 mm.

According to a further aspect, the insole is defined by a toe end facing the wearer's toe, a heel end facing the wearer's heel and a central axis extending from the toe end to the heel end. According this aspect, the projection has a front end facing the wearer's toe, a rear end opposed to the front end and a front/rear axis extending from the front end to the rear end, said projection having an elongate shape defined by a length along the front/rear axis which is greater than a width transverse to said front/rear axis with a length:width ratio which is greater than 1:1 or in a range of about 1.2:1 to about 3:1. Furthermore, according to a further aspect, we disclose that the insole is configured whereby the front/rear axis of the projection may be angled on a horizontal plane relative to the central axis within a range which is one of: 5° to 75°, 5° to 50°, 5° to 35° or 25° to 35°, wherein said horizontal plane is parallel to a flat ground surface when said shoe is placed thereon.

According to a further aspect, we disclose a method for treating a disorder of the foot comprising the steps of fitting an insole within a shoe, whereby the insole comprises the insole as described herein and the method comprises weight bearing on said insole during walking or running. The disorder may be cuboid syndrome, hallux valgus, plantar fasciitis, bunions, hammertoe, or foot pain.

The insole disclosed herein allows the foot to actively work inside the shoe, thereby improving strength and mobility of the foot. We discovered that this narrowly targeted pressure whereby the cuboid bone becomes unlocked in the middle of a stride reduces symptoms of foot pain and developed more movement in the foot that again decreases ankle strains and sprains through muscle build up. This also takes the strain away from the knees, thereby protecting the cartilage and menisci.

The present insole acts as an assistive device that acts as a passive wedge that promotes the unlocking of the cuboid and rotation of navicular during the stance phase, promoting this midfoot function. The advantage to athletes is that there is considerably more hamstring recruitment in a toe-foot function (pushing off using the big toe) and it stimulates strengthening of the intrinsic foot musculative. There is a focus on Biceps Femoris activity in the heel-foot function (pushing off outside of foot). Foot problems such as bunions, plantar fascitis, IT band issues, groin issues (esp. pectineus) can all trace their roots to heel-foot function and rigidity of the mid foot.

By passively forcing the midfoot to move, the present insole and method provides an improvement of the “Windlass Effect” on the toes and especially the big toe for improved propulsion. As well, the present insole also affects the deep compartment of the foot: the Flexor Hallicus Longus sesamoid is able to move in front of the MTP1 Joint and create a passive support to the arch like a string on a bow. In “shod” populations, this does not occur as readily and the intrinsic muscles especially Flexor Digitorum Brevis, strain to support the foot leading to conditions such as plantar fascial strain and heel spurs.

Directional references herein are used for convenience of description, and are in relation to an insole positioned horizontally, as it would be when installed inside a shoe on a level surface. The “forward” direction faces the front of the user, towards the user's toes and “rearward” refers to the direction facing the user's heels and backside. “Lateral” refers to directions that are horizontally perpendicular to the front/rear axis towards the left and right, perpendicular to the sagittal plane of the user.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts walking motion of a normal human gait.

FIG. 2 depicts contact points of a foot during the walking motion of FIG. 1.

FIG. 3 shows a skeleton of a human foot.

FIG. 4 shows a skeleton of a human foot.

FIG. 5 is a schematic drawing of a dome-shaped projection for use in the present insole.

FIG. 6 is a plan view from above of an example of an insole.

FIG. 7 is a plan view from above of a kit of parts according to one example.

DETAILED DESCRIPTION

Referring to FIGS. 5-7, an example of an insole 1 is described. Insole 1 comprises an upper surface 2 which faces upwardly in use to contact the user's foot and an opposing lower surface 4 which faces downwardly in use to contact the upper surface of the shoe insole (not shown). In one example, insole 1 is substantially flat and of substantially the same thickness throughout, apart from a single dome-shaped projection 30, discussed below, which projects upwardly from the insole. Optionally, insole 1 may have small structural features such as an upwardly-projecting rim around its periphery which cradles the user's foot, a heel depression which cradles the user's heel, or a transverse ridge which supports the base of the user's toes.

Lower surface 4 may be essentially flat, although it may be somewhat curved to accommodate the curvature of a conventional shoe or sandal. Insole 1 is generally elongate to match the configuration of a conventional show whereby insole 1 comprises a toe end 6 and an opposing heel end 8. A longitudinal axis 10 extends between the toe and heel ends, which is horizontal when insole 1 is placed on a horizontal surface and is aligned with the direction of travel of the user when walking or running, i.e. parallel the sagital plane of the user. For purposes of reference, a horizontal lateral axis 12 is perpendicular to and bisects longitudinal axis 10.

Insole 1 has a configuration that substantially matches a conventional shoe insole in order to easily fit inside a convention shoe, sandal or other footwear. The term “shoe” as used herein refers to any footwear that can accept an insole of the type described herein. Insole 1 is configured to be inserted into a shoe or, as discussed below, be built into an otherwise conventional shoe. For this purpose, the configuration of insole 1 generally matches the existing insole of a conventional shoe. Alternatively, insole 1 may be configured to fit into a specialty shoe having a non-conventional configuration.

Insole 1 may be a “full” insole extending substantially the full length of the user's foot and shoe, or a partial insole which terminates at the approximately the ball of the user's foot.

Insole 1 has a single projection 30 the projects upwardly from upper surface 2 (see FIG. 5). The term “single” as used herein means that there are no other projections protruding upwardly from upper surface 2 and the remainder of upper surface 2 is substantially flat, apart from structural features described herein. Referring also to FIGS. 3 and 4, projection 30 of insole 1 is positioned directly target location 27 of the user's foot (see FIG. 4), which is under the medial side of the cuboid bone 20 of the shoe wearer where the cuboid bone 20 borders the navicular bone 22 on one side and the calcaneus bone 24 on the other side. FIGS. 3 and 4 show the human foot in which all of the bones essential to the invention are designated and, further, shows the goal of the projection corresponding to the present invention in one of the preferred embodiments thereof. FIGS. 3 and 4 depict an axis b that intersects with the longitudinal foot axis a to enclose an angle α, with the point of intersection being at target location 27. The respective axes a and b are on a common horizontal plane. The range of angle α is discussed below. Projection 30 is configured and located on insole 1 to apply a targeted pressure that bears specifically on target region 27.

The projection 30 (shown schematically in FIGS. 5 and 6) comprises a resilient member that resiliently compresses when the user's weight bears down on it. For example, it may comprise an elastic plastic and/or gel material such as polyurethane having, in one example, a hardness in the range of about 30 to 40 when measured on the Shore A 00 scale. Projection 30, including a film that may cover the dome, may have a hardness in the range of 50 to 60 when measured on the Shore A 00 scale. It will be appreciated that in other examples, a different range of hardness may be selected. Structure 30 comprises a base 32 which merges with upper surface 2 of insole 1 and a crest 34 which comprises the uppermost portion of projection 30. Projection 30 has a generally trapezoid shape in plan view (seen from above) comprising a rounded upper rear edge 36, an opposing upper forward edge 38 that is wider than rear edge 36 in the lateral (transverse) dimension and opposing side edges 40 and 42 that splay outwardly away from each other and forwardly, whereby 30 is widens transversly direction from rear to front. The rounded shape of front and rear edges 38 and 36 is provided primarily for user comfort and to prevent sharp corners which could otherwise allow projection 30 to peel off from insole 1. The first side edge 40 of projection 30 faces the sagital (central front to rear and vertical) plane of the user whilst the opposing second side edge 42 faces outwardly from the sagital plane. As seen in FIGS. 6 and 7, first side edge 40 is substantially parallel the sagital plane whilst opposing side edge 42 is angled forwardly and outwardly from the sagital plane.

In one example, projection 30 comprises a lower region 44 that tapers upwardly and inwardly at a generally constant slope on all sides and an upper region 46 that terminates in rounded crest 34. In one example, crest 34 is circular or square. As such, projection 30 has a configuration that somewhat resembles a truncated pyramid with a trapezoid base and an elongated, rounded peak.

In another example, upper region 46 and crest 34 have an elongate configuration, which may be oval, lozenge-shape or generally rectangular in plan view (i.e. when seen from above, looking downwardly. Crest 34 thus has an elongate shape with a horizontal central axis 50 that extends from the front to rear thereof and a horizontal transverse axis 52 that is perpendicular to the central axis and which is shorter than central axis 50. In this example, the longitudinal-transverse ratio is greater than 1:1. The ratio may be up to 4:1 or preferably in a range of from 1.2:1 to 3:1.

Central axis 50 is disposed at an angle θ relative to central axis 10 on a horizontal plane which in one example is in the range of 5° to 35°, more preferably in the range of 25° to 35°. Angle θ diverges outwardly away from the sagital plane and forwardly. Angle θ of projection 30 is aligned with angle α of the user's foot.

According to one aspect, the inventors have shown that in one example, the base surface of the projection 30 is particularly effective when the area of insole 1 covered by base 32 is a maximum of 20%, or even a maximum of 15%, of the insole surface or the surface of the shoe insole, if insole 1 covers less than the full amount of the shoe insole. In particularly preferred embodiments, it is even possible to reduce the base surface of the projection 30 to a surface of 10% or less, particularly preferably even to a surface in a range from less than 4% to 8%, of the insole surface. In this case, however, the wearer of a shoe of this kind should train intensively to run on these insoles according to the invention with projection 30 which have a particularly drastically reduced base surface because otherwise it could be less comfortable under certain circumstances.

The top to bottom height h of the projection 30 relative to upper surface 2 is preferably in a range from 3 to 20 mm. In one embodiment, h is about 8, 10 or 13 mm. In another embodiment, h is 4, 6 or 15 mm.

Preferably, projection 30 has an elongate shape characterized by an elongate ridge-like apex 34 forming its uppermost surface. Apex 34 has a longitudinal-transverse ratio which is greater than 1:1. For example, this ratio may be about 4:1. In experiments, this 4:1 ratio was shown to be particularly effective in the trials. In these experiments, insole 1 was configured such that longitudinal axis 50 of the projection 30 extends along the medial edge of the cuboid bone 20. The medial edge of cuboid bone 20 angles laterally from the central foot axis a at an angle α. To align apex 34 with angle α, apex 34 is angled within a horizontal plane relative to the longitudinal axes 10 (of insole 1) preferably is in the range of 5° to 35°, particularly preferably an angle θ of 25° to 35°, on a horizontal plane, relative to the longitudinal axis 10 of insole 1.

According to other aspects, angle θ is within a range which is one of: 5° to 75°, 5° to 50°, or 5° to 35°. An angle within these ranges is selected to correspond to the angle of the cuboid bone relative to the heel-toe axis of the foot. This aspect serves to better align the projection with the medial side of the cuboid bone where that bone borders the navicular bone on one side and the calcaneus bone on another side, to thereby improve the “unlocking” effect noted above.

For an illustration of projection 30 as a truncated cone, reference is made particularly to FIG. 6. The position of angle θ is illustrated particularly in FIGS. 5 and 6.

In one embodiment, projection 30 is permanently attached to upper surface 2 of insole 1. This can be achieved in that the insole and projection 30 are fabricated separately and subsequently indissolubly glued; this can also be achieved in that the insole and projection 30 are integrally cast, moulded or 3-D printed from a suitable plastics material without limiting in any way to these two possibilities.

In a second embodiment, upper surface 2 of insole 1 and projection 30 both have connection components, and the connection components of the insole are formed with the connection components of the projection 30 in such a way that insole 1 and projection 30 are connected to one another so as to be difficult to detach. This detachability permits exchanging the projection 30, for example in case of wear or when a different hardness and/or a different outer shape or dimension is desired. In this case, the connection components between insole and projection 30 may comprise any suitable connection means such as hook-and-loop (such as Velcro™) strips.

Another possible connection means consists of mating grooves and ridges between surface 2 and projection 30. The grooves/ridges may extend at an angle of 80° to 100° to the longitudinal axis 50 of the projection 30. The grooves may be disposed on a substantial part of surface 2 that extends to the outer edge of the insole.

When grooves in the base 32 of the projection 30 are selected as connection components between insole and projection 30, it is preferable when these grooves extend along the longitudinal axis 50 of the projection 30. Snap-in elements in the grooves prevent an unintentional slipping of the projection 30 relative to the insole on one hand and facilitate an exact alignment of the projection 30 relative to the insole on the other hand.

When the connection components between the insole and projection 30 are realized by grooves/ridges, it is particularly preferable when the recessed grooves are undercut and the ridges are formed so as to widen outward in a corresponding manner.

It is possible to form the insole as an integral component part of a shoe. In this case, the insole according to the invention is glued and/or sewed to the outsole of a shoe and, as the case may be, also to the outer material of this shoe.

The insole may also be constructed as an insert for certain shoes. In this case, it is also possible for the insole to comprise a so-called 314 sole which can be fastened to a complete insole inside a specific shoe by means of double-sided adhesive tapes. In so doing, it is common to shorten ¾ soles of this kind in the front and, if necessary, on the sides until they fit into the given shoe. In the case of a shortened insole of this nature, the relative size dimensions provided herein are modified in a corresponding pro rata fashion. In other words, in the case of an insole which is ¾ length of the existing shoe insole, a dome which in a full size insole would comprise 25% of the insole area, would now comprise about 33% of in the insole area.

According to a further aspect, we disclose a method of treating cuboid syndrome in a human subject by applying a targeted pressure on the sole of the user's foot against the CC joint. The targeted pressure is applied by weight bearing on an insole in which the insole has a single projection that is of the type described in the present examples, and is configured to apply a targeted pressure directly and specifically against target area 27 of the user's foot. As a result, an increased pressure is applied against this target area relative to adjacent areas of the foot.

According to a further aspect, the method of treating comprises using a sequence of insoles and/or removal projections 30 according to the present disclosure wherein the respective heights of projections 30 are progressively higher. Optionally, the horizontal areas of the crest portions 34 of the projection may be progressively smaller, thereby sequentially applying a progressively more targeted pressure against the user's sole. For example, a sequence of three insoles may be used, in which the projections 30 are progressively higher and/or smaller in horizontal area. The timing of the use of the different insoles may be predicated in feedback from the user, whereby a new insole is used when the user becomes comfortable and acclimated to a given projection configuration.

Referring to FIG. 7, according to a further aspect, we disclose a kit of parts consisting of an insole and multiple detachable projections 30 comprising different heights. Such a kit may optionally be specifically designed for use with the method described above. For example, the kit may comprise an insole and multiple detachable projections 30 having configurations that allow the user to use a sequence of projections that are progressively thicker (higher) and/or smaller in horizontal area.

Alternatively, the projections 30 may be integral with insoles 1 whereby the kit comprises multiple insole/projection units having the dimensions and properties described above.

In one aspect, the targeted pressure is applied to foot region 27 by providing an insole 1 in which projection 30 is relatively small in horizontal area in relation to the horizontal area of the entire footbed and is also located quite precisely relative to the user's foot. The projection is located such that when used, it is directly beneath the medial side of the cuboid bone where that bone borders the navicular bone on one side and the calcaneus bone on another side. When the user bears weight on the insole during motility (eg walking or running) or when standing (non-motile), this applies targeted pressure against that location of the user's foot for unlocking of the cuboid bone during the stance phase of the user's stride. The method allows the foot to actively work inside the shoe, thereby improving strength and mobility of the foot. This narrowly targeted pressure whereby the cuboid bone becomes unlocked at the end of a stride reduces symptoms of foot pain and developed more movement in the foot that again decreases ankle strains and sprains through muscle build up. This also takes the strain away from the knees, thereby protecting the cartilage and menisci.

In testing of the present method, examples of the presently-described insoles 1 were tested on volunteers who used the examples for extensive running and walking activities. In most cases, users reported less pain when using the present insole as compared with previous orthotics. As well, several of the test subjects found that their bunions felt better after applying the present method.

Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto. 

1. An insole for a shoe, comprising: a lower side configured to face a shoe outsole; an upper side opposite the back side for contacting the sole of a shoe wearer's foot; and a projection projecting upwardly from the upper side; wherein the insole is configured to position the projection at a location of the user's foot directly under a medial side of the cuboid bone where the cuboid bone borders a navicular bone on one side and a calcaneus bone on another side wherein a targeted pressure is applied to said location of the user's foot whereby there is achieved an unlocking of the cuboid bone during the user's stride.
 2. The insole of claim 1, wherein the projection has a base which has a size relative to the size of the insole which is up to about 25%, 20% or 15%, or which is in the range of about 4% to about 8% thereof.
 3. The insole of claim 2, wherein the projection has a base which has a size relative to the size of the insole which is up 15% thereof.
 4. The insole of claim 2, wherein the projection has a base which has a size relative to the size of the insole which is in the range of about 4% to about 8% thereof.
 5. The insole of claim 1, wherein the projection has a height in a range from about 3 mm to about 20 mm.
 6. The insole of claim 1, wherein the projection is permanently connected to the insole or comprises an integral component part of the shoe.
 7. The insole of claim 1, wherein the projection is releasably connected to the insole.
 8. The insole of claim 1 wherein the insole is defined by a toe end facing the wearer's toe, a heel end facing the wearer's heel and a central axis extending from the toe end to the heel end, wherein the projection has a front end generally facing the wearer's toes, a rear end opposed to the front end and a front/rear axis extending from the front end to the rear end, wherein the upper surface of said projection comprises an elongate ridge defined by a length along the front/rear horizontal axis of the ridge which is greater than a width transverse to said front/rear axis with a length:width ratio which is greater than 1:1 or in a range of about 1.2:1 to about 3:1.
 9. The insole of claim 8 wherein said ridge has a length/width ratio of about 4:1.
 10. The insole of claim 8 wherein said insole is configured whereby the front/rear axis of the ridge is angled on a horizontal plane relative to the central axis within a range which is one of: 5° to 75°, 5° to 50°, 5° to 35° or 25° to 35°, wherein said horizontal plane is parallel to a flat ground surface when said shoe is placed thereon.
 11. The insole of claim 10 wherein the front/rear axis of said ridge is disposed at a horizontal angle of about 25° to 35° relative to the central axis of the insole.
 12. The insole of claim 10 wherein the front/rear axis of said ridge is disposed at a horizontal angle relative to the central axis of the insole which substantially matches the angle by which medial edge of the cuboid bone of the human foot angles laterally from a central axis of the human foot, wherein the central axis is defined by an axis extending from the middle of the calcaneous bone to the tip of the index (second) toe.
 13. A kit for assembling an insole for a shoe comprising: a base comprising a lower side configured to face a shoe outsole and an upper side opposite the back side for contacting the sole of a shoe wearer's foot; and a plurality of projection members configured to selectively assemble to the base to project upwardly from the upper side; wherein the assembled insole comprises a single one of said projection members and is configured to position the projection member at a location of the user's foot directly under a medial side of the cuboid bone where the cuboid bone borders a navicular bone on one side and a calcaneus bone on another side whereby a targeted pressure is applied to said location of the user's foot whereby there is achieved an unlocking of the cuboid bone during the user's stride.
 14. The kit of claim 13, wherein the projection member has a base which has a size relative to the size of the insole which is up to about 25%, 20% or 15%, or which is in the range of about 4% to about 8% thereof.
 15. The kit of claim 14, wherein the projection has a base which has a size relative to the size of the insole which is up 15% thereof.
 16. The kit of claim 15, wherein the projection has a base which has a size relative to the size of the insole which is in the range of about 4% to about 8% thereof.
 17. The kit of claim 14, wherein the projection member has a height in a range from about 3 mm to about 20 mm.
 18. The kit of claim 14, wherein the assembled insole is defined by a toe end facing the wearer's toe, a heel end facing the wearer's heel and a central axis extending from the toe end to the heel end, wherein when assembled the projection has a front end generally facing the wearer's toes, a rear end opposed to the front end and a front/rear axis extending from the front end to the rear end, wherein the upper surface of said projection comprises an elongate ridge defined by a length along the front/rear horizontal axis of the ridge which is greater than a width transverse to said front/rear axis with a length:width ratio which is greater than 1:1 or in a range of about 1.2:1 to about 3:1.
 19. The kit of claim 18, wherein said ridge has a length/width ratio of about 4:1.
 20. The kit of claim 18, wherein said insole when assembled is configured whereby the front/rear axis of the ridge is angled on a horizontal plane relative to the central axis within a range which is one of: 5° to 75°, 5° to 50°, 5° to 35° or 25° to 35°, wherein said horizontal plane is parallel to a flat ground surface when said shoe is placed thereon.
 21. The kit of claim 18, wherein the front/rear axis of said ridge is disposed at a horizontal angle of about 25° to 35° relative to the central axis of the insole.
 22. The kit of claim 18, wherein the front/rear axis of said ridge is disposed at a horizontal angle relative to the central axis of the insole which substantially matches the angle by which medial edge of the cuboid bone of the human foot angles laterally from a central axis of the human foot, wherein the central axis is defined by an axis extending from the middle of the calcaneous bone to the tip of the index (second) toe.
 23. A method for treating a disorder of the foot comprising the steps of fitting an insole within a shoe whereby the insole comprises the insole of claim 1, said method comprising weight bearing on said insole during walking or running.
 24. The method of claim 23 wherein the insole comprises the insole of claim
 8. 25. The method of claim 23 wherein the insole comprises the insole of claim
 12. 26. The method of claim 23 wherein said disorder is cuboid syndrome, hallux valgus, plantar fasciitis, bunions, hammertoe, or foot pain.
 27. The method of claim 26 wherein said disorder is cuboid syndrome. 